This invention relates to photographic processing and is more particularly concerned with the application of photographic processing solutions to the material to be processed.
It is known to apply processing solutions to the material to be processed by passing the material through a number of tanks and reservoirs containing the required solutions. Such arrangements require large volumes of processing solutions in order to operate effectively. This means that the processing solutions used need to be stable for relatively long periods of time. It is also difficult to vary the process cycle.
To overcome the necessity of maintaining large tanks of relatively unstable solution further methods were developed in which the solutions are applied to the surface of the material being processed. In this method the processing chemicals required can be kept separately until just before they are needed.
It is an objective of the invention to provide satisfactory processing of color film or paper without the need for large tanks (2 liters or more) as used in conventional processing. This objective can be achieved by applying small volumes of processing solution directly to the surface of the photographic material. This method however has several attendant problems which must be solved in order to make such surface application practical. The problems found with surface application are that processing is not uniform if small volumes are used, processing is slow because there is no agitation after application of the solution and the chemical consumption is high because there is no mixing of the solution.
It is an object of the invention to provide a method and apparatus which overcome the problems mentioned above.
According to the present invention, there is provided an apparatus for processing light sensitive material, the apparatus comprising at least one movable applicator for applying a fixed volume of processing solution to the surface of the material to be processed, means for moving the applicator and the material relative to each other to enable mixing of the solution on the surface, and means for moving the at least one applicator from a position in contact with the material to a position out of contact with the material such that the process cycle can be varied.
The invention described overcomes the problems of the prior art and provides a practical surface application method. The method is called xe2x80x9cdynamic surface applicationxe2x80x9d in which mixing of the applied solution occurs during the whole process time.
The invention provides a method of high agitation while still providing good uniformity. It is particularly suitable for xe2x80x9csingle usexe2x80x9d chemistry where the solution is not reused.
The method provides a process which can accommodate any process cycle. The process cycle can be varied almost instantly by changing the number of applicators for a given stage of the process by moving the applicators in and out of contact with the surface of the material being processed. More than one applicator can be used for each stage of the process or a single applicator can be used for all the solutions in the process. The method is equally applicable to film and paper and these materials can be processed in the same processor.
Both the solution and the web of material can be heated to a higher temperature than is possible using a large tank of solution. This allows more rapid processing to take place. Furthermore, since only small volumes of solution are required for each stage of the process unstable processing solutions may be used.
The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments, in connection with the accompanying drawings.